Lotus 7

Just joined the forum and just re-joined the ranks of Audi ownership.....took a long break from Audi ownership and just got pulled back in by a very cheap well looked after A4.
Always loved the look of the A4 and was easily tempted with the one that is sitting outside my shop right now. The car itself is fairly well looked after however after the owner replaced a leaky rad and put in a new thermostat, the possible real culprit has reared it's ugly head......head gasket is gone. Vehicle runs great but after a minute or two of warm up the cooling system builds pressure and vomits coolant out the overflow (not an overflow cap).....a small amount of steam from the tailpipe also present. I am going to pressure test the cooling system and do a leakdown tomorrow just to pinpoint the problem hoping that I can narrow the repair cost down but feel I will being going the full monty! My long winded question is has anyone done a top end rebuild on a 2.8 V6....minor or major? And if so anything I should be looking out for???? any tips or tricks???? Anything I can do to give it some extra zing while I have the heads off (within reason as I am not looking to spend a bunch in an attempt to give the wife a car she will never appreciate from an engineering standpoint)or even some other cheap tuning tricks that are performance related.....not the all to common stick an oil drum in place of a muffler 'coz it's soundz phat' trick. I may only keep this thing for a year or two at best and don't want to sink a fortune into it but do want to have a little fun.
Thanks for any advice and help you can give......The Volvo will soon be dead....Long Live the Audi!

MartinH

This link is for 12v Audi engines specifically and not the A4 in particular. However I followed it when changing the head gaskets on my 96 Quattro a few years ago and came out at the end with a successful job.

http://www.12v.org/maintenance/repairs/headgasket.php


Main things to consider while you are in that deep is to change the timing belt, water pump etc and check the thermostat is installed correctly and working. Also vaccum hoses at the back of the engine will be kaput by now unless they have been replaced before. Take some pics of their routing before you take them apart. Yeah, and clean the EGR channel in the TB while it is off.

Lotus 7

MaritnH

Thank you very much for the link and your advice. I was intending on doing the service items while I have it apart. You mentioned the thermostat being installed correctly.....is it that confusing on this model? I did a couple of the old turbo straight fives several years ago and it was a no brainer however I have not looked at the layout for this system.

Thanks again.

Lotus 7

Well it now looks like the thermostat was never replaced (previous owner a former mechanic had someone else do the rad and supposedly the t-stat....fleeced by his own kind how poetic) as the previous owner had stated. I checked hoses and the bottom hose stays ice cold while the top slowly warms and pukes coolant out the overflow. Leakdown test showed no signs of any issues when engine was warm and coolant pressure test indicated the same other than what I now imagine is a jammed closed thermostat. The previous owner stated the car first showed these signs on a day when we had a nice cold snap here in the Great White North so it is sounding more plausable all the time. I am hoping someone can point me in the right direction for changing the thermostat without having to remove the timing belt and going through the emotional trauma of re-setting everything???????

MartinH

You didn't mention if you knew if the timing belt had been replaced within living memory. If you have no record of that and you have to replace the thermostat, then it is highly recommended you replace the belt at the same time as the thermostat is behind it. Also the belt tensioner and water pump.
A lot less emotional trauma replacing these items than having the timing belt break or water pump sieze (I had the latter and it pretty much ruined my weekend)!

Pete@ECSTuning

I completely agree. I have a 12v as well. I dove in there for a thermostat 10k miles ago and wish I had just done the TB too. You pretty much do a timing belt job to get to the thermo so for an extra 10 minutes time you could do a thermostat and timing belt. You should do one in this case especially if you don't know if it was done recently.

We carry an inexpensive timing belt kit that includes the belt, thermostat and water pump as well as the rollers that are known to sieze up. Click here for 12v Timing Belt Kits

quattrone

If you are careful, you can loosen the timing belt tensioner and ease the belt forward partway on the cam sprockets enough to get at the t-stat without removing the belt. To be safe, mark the t-belt and sprockets before you begin in case something slips! Good Luck...

turbo510

I can tell you from experience that something WILL slip, so paint marks on the belt, sprockets, and valve covers are essential. As soon as I loosened the timing belt roller, the belt jumped several teeth on the passenger-side cam sprocket. Fortunately, there were mis-aligned paint marks to match up.

4Driver4

This is a horrible idea. Use the timing belt tools to get the belt on correctly.

Lotus 7

Thanks for all the advice Audi dudies!
I am considering doing the whole job while in there, my biggest hurdle now are the timing belt tools. I cannot find anyone here in my City (dealership, independent, snap-on guy) that will rent me these tools, Blauparts will not loan across the border and I dont feel like buying the set but may have to. If some one had dimensions from the tools I could fabricate the cambar fairly easily, I need to see the crank pin to consider if I could turn it or can find something off the shelf to modify....I will probably do the crank and cam seals also and have a puller, seal remover and drivers etc.....Anyone know of anywhere in the province of Ontario, Canada that rents these.....I am in London to be exact? Maybe i will get in the rental business....any takers?